Generally, the present invention relates to the distribution of subscriber program material, and more particularly to distribution of television program material using wireless broadband loops and a bidirectional antenna array.
Conventionally, the use of wireless communication is restricted to cellular telephone systems for voice and limited data service. Recently, however, wireless communication services are being used for unswitched xe2x80x9cbroadcastxe2x80x9d television distribution. These systems use a cellular structure with each cell transmitting in the direction of potential subscribers. Two of these systems include an early analog approach, referenced in xe2x80x9cThe M3 Saxmundham Demonstrator-Multichannel TV Distribution by mm-Waves,xe2x80x9d M. Pilgrim, R. P. I. Scott, R. D. Carver, and B. J. Ellis, British Telecom Tech., J. Vol. 7 No. 1, January 1989, and a digital broadcast approach, Application of Hye Crest Management, Inc. before the FCC, File No. 10380-CF-P-88, released Jan. 18, 1991, the latter being designed to take advantage of highly compressed digital video/audio codecs.
These approaches as well as other more recent developments in television and data signal broadcasting, allow subscribers to select information programs from a set of broadcast program materials. Once selected, a data stream of program material is received by the subscriber in a continuous downstream feed. Video on demand and pay-per-view systems for example, permit users to select a broadcast channel transmitting a movie or other program material for viewing. The channel is selected at the viewer""s home, and the program is received at a designated, scheduled time. Conventionally, the downstream data flow is controlled by the distribution source, and the subscriber has little or no input as how the data stream is received. In other words, while the subscriber can request the program material or movie, he cannot start or stop the stream once it has begun. In addition, the subscriber cannot affect the downloading speed or sequence of the downloaded signal. Further, because conventional transmission facilities continually broadcast the material on a given channel, scrambling or blocking techniques are often required to prohibit unauthorized access of the material.
Conventional broadcast systems of this type also do not offer an upstream signaling capability that allow the user to transmit data via the network. If available, this upstream signaling capability could permit subscribers to utilize the high bandwidth transmission rates of a centralized control center for their own personal broadcast. Services, such as desktop video conferencing and home data transmission uplink, could be initiated from the subscriber""s location and transmitted using a two-way communication center.
There is therefore a need for an economical approach for distributing a wide range of subscriber services to customers without access to conventional broadband wireline distribution systems. The solution should provide a low-powered, high bandwidth switched service system with the ability to provide the services to a large number of subscribers. The system should give subscribers both upstream and downstream signaling capabilities with control over the downstream program signal once it is requested. Preferably, the solution should also allow subscribers to use the capabilities of the two-way broadcasting center via upstream signaling. Finally, the solution should effectively deny unauthorized access to source material.
Systems and methods consistent with the present invention permit distribution of subscriber services such as voice, video, and data by using millimeter wireless loops. Systems and methods of the present invention distribute the subscriber services from a cell center to a number of subscriber units. The cell center includes a switch mechanism that changes to a particular channel at the request of the subscriber. The requested service is then downloaded to the subscriber and processed. The cell center also includes a bidirectional antenna array specifically configured to provide coverage for a large number of subscribers. The antenna array includes a number of antenna units with alternate horizontal and vertical transmission modes. Each bidirectional antenna transmits downstream services and receives the upstream signaling requests from the subscriber units.
Specifically, the invention provides a communications system having a headend source of stored information signals coupled to a wideband wireless loop network. The network comprises: a plurality of cell centers each assigned to a subscriber service area including communication device configured to communicate with subscriber units within a designated subscriber service area; a plurality of antennas each dedicated to a segment of the subscriber service area and operable to communicate over a common frequency channel, and wherein the antenna corresponding to adjacent segments of the service area operate in different transmission modes; and a plurality of subscriber units, each unit including a receiver configured to receive a downstream information signal from an antenna, and a transmitter configured to transmit an upstream signal request to an antenna.
In another aspect the invention provides a method for providing subscriber services to a number of subscribers in a wideband wireless loop network having a headend source of stored or transported information signals coupled to a wideband wireless loop network, the network including a plurality of cell centers each providing service to a number of service area segments. The method comprising the steps of: initiating an upstream signal request at a subscriber unit located within a service area segment sending a polling message to subscriber units in the service area segment from a cell center to determine the presence of the upstream information request, wherein the cell center services the service area segment containing the requesting subscriber unit; transmitting, to the cell center, the upstream signal request upon the receipt of the polling message; switching, upon receipt of the upstream signal request, a selection device to a subscriber service channel, wherein the subscriber service channel broadcasts a subscriber service; transmitting the subscriber service, via the selected subscriber service channel, to the requesting subscriber unit in a downstream information signal; and receiving the downstream information signal at the requesting subscriber unit.
The summary and the following detailed description should not restrict the scope of the claimed invention. Both provide examples and explanations to enable others to practice the invention.